How to use agg() function with GroupBy() In Python
Here we have to import the sum function from sql.functions module to be used with the aggregate method.
Syntax: dataframe.groupBy(“group_column”).agg(sum(“column_name”))
where,
- dataframe is the pyspark dataframe
- group_column is the grouping column
- column_name is the column to get sum
Python3
# importing module import pyspark # importing sparksession from pyspark.sql module from pyspark.sql import SparkSession # import sum from pyspark.sql.functions import sum # creating sparksession and giving an app name spark = SparkSession.builder.appName( 'sparkdf' ).getOrCreate() # list of student data data = [[ "1" , "sravan" , "IT" , 45000 ], [ "2" , "ojaswi" , "CS" , 85000 ], [ "3" , "rohith" , "CS" , 41000 ], [ "4" , "sridevi" , "IT" , 56000 ], [ "5" , "bobby" , "ECE" , 45000 ], [ "6" , "gayatri" , "ECE" , 49000 ], [ "7" , "gnanesh" , "CS" , 45000 ], [ "8" , "bhanu" , "Mech" , 21000 ] ] # specify column names columns = [ 'ID' , 'NAME' , 'DEPT' , 'FEE' ] # creating a dataframe from the lists of data dataframe = spark.createDataFrame(data, columns) # Groupby with DEPT and NAME with sum() dataframe.groupBy( "DEPT" ).agg( sum ( "FEE" )).show() |
Output:
Pyspark dataframe: Summing column while grouping over another
In this article, we will discuss how to sum a column while grouping another in Pyspark dataframe using Python.
Let’s create the dataframe for demonstration:
Python3
# importing module import pyspark # importing sparksession from pyspark.sql module from pyspark.sql import SparkSession # creating sparksession and giving an app name spark = SparkSession.builder.appName( 'sparkdf' ).getOrCreate() # list of student data data = [[ "1" , "sravan" , "IT" , 45000 ], [ "2" , "ojaswi" , "CS" , 85000 ], [ "3" , "rohith" , "CS" , 41000 ], [ "4" , "sridevi" , "IT" , 56000 ], [ "5" , "bobby" , "ECE" , 45000 ], [ "6" , "gayatri" , "ECE" , 49000 ], [ "7" , "gnanesh" , "CS" , 45000 ], [ "8" , "bhanu" , "Mech" , 21000 ] ] # specify column names columns = [ 'ID' , 'NAME' , 'DEPT' , 'FEE' ] # creating a dataframe from the lists of data dataframe = spark.createDataFrame(data, columns) # display dataframe.show() |
Output: